ACTG 362 started as a randomized, double-blind, placebo-controlled trial designed to test whether people who had large increases in CD4 cells with HIV treatment should continue to take azithromycin prophylaxis to prevent MAC infection. The data and Safety Monitoring Board (an independent committee who reviews studies) looked at the results available so far from ACTG 362 and found that the risk of developing MAC is very low in people who have had increases to more than 100 CD4 cells. Therefore, the study team decided to ask participants to stop taking the study medications unless their CD4 counts have dropped below 50 cells and continue to be followed on study for approximately 2.5 years (until April 2002). The study will no longer evaluate the possible long-term benefit of azithromycin to prevent MAC infection. The results of the DSMB review suggest that the risk of MAC is so low in the subjects not taking the active drug azithromycin that it was unlikely the study would ever tell if there is a benefit of azithromycin for the prevention of MAC disease in people who have an increase in T cells above 100 cells. Therefore, the main purpose of this study now will be to see if taking a HAART regimen (highly active antiretroviral therapy) for a long period of time will continue to prevent AIDS defining complications and serious bacterial infections. Increased levels of fats (cholesterol and triglycerides) in the blood have been seen in some patients taking HIV drugs for a long time, and may be linked to possible increased risk of heart attacks. A secondary purpose of continuing to be followed on this study will be to determine the rates of heart attacks and strokes among subjects enrolled in the study. Because the subjects in this study have been on HIV medication (and about half have been on azithromycin) for a long time, continuing the study may help to determine if having taken azithromycin will have a effect on the risk of heart attacks and strokes among the study subjects.